Our invention relates to the field of merchandising machines and more specifically to an improved drive system for an article dispensing merchandising machine having generally circular article supply carriers adapted to be driven on each operation of the machine to deliver an article of merchandise.
U.S. Pat. No. 4,087,020 issued May 2, 1978, to Merrill Krakauer, for ARTICLE VENDING MACHINE HAVING ROTARY STORAGE COMPARTMENTS discloses a merchandising machine including a plurality of merchandise storage and delivery modules mounted for movement on the machine cabinet between a housed position in the machine cabinet and a position at which the units are out of the cabinet to facilitate loading thereof. Each module includes an upper and a lower storage and delivery unit, each of which includes a generally circular merchandise supply carrier adapted to be stepped through a distance corresponding to one compartment of the carrier in the course of a delivery operation to position a compartment thereof adjacent to the inlet of an escrow display assembly, having a display surface and a door structure made up of a lower door and an upper door. In response to a step of movement of a carrier, the associated door structure moves to cause the lower door to release an article from the display shelf and the upper door to prevent the next article from falling onto the display surface. When the article has been dispensed, the door structure closes the bottom of the escrow surface and permits the next article to move onto the surface. In addition, each unit includes a product pusher adapted to be actuated to move into a compartment positioned adjacent to the escrow system positively to move the product out onto the escrow surface.
The machine described in the patent cited hereinabove includes a drive system for selectively operating the units of the machine successively to step the merchandise carrier and thus operate the escrow mechanism and then to operate the pusher to cause it to move into the compartment positively to force an article out into the escrow mechanism. More specifically, respective upper and lower carriages are mounted for swinging movement adjacent to the upper and lower units of the machine. Each carriage supports a plurality of selectively actuatable members, each of which includes a "T" head. In the inactive position of each of these selector members, the "T" heads ride idly by their associated units. In the active position of a "T" head, as its associated carriage swings with relation to the corresponding unit, one side of the "T" head enters a cam track to guide the head along such a path that the other side of the "T" head first releases a unit locking pawl and then engages a tooth on the carrier to rotate the member through a distance corresponding to one compartment and then to drive the product pusher.
While the drive system shown in the cited patent functions satisfactorily, it incorporates a number of defects. First, it requires that the delivery units be relatively accurately located relative to the selecting elements, when the modules are moved back into the cabinet after loading of their units. Secondly, the swinging motion of the carriage as it drags the "T" head along the cam path, requires that the parts be built up to a point at which they are excessively bulky and weighty. Thirdly, the mechanism for selectively actuating the coupler elements and for releasing the coupler elements is relatively complicated. Further, any mid-cycle jam requires dismantling of the machine.
We have invented an improved drive system for a merchandising machine of the type employing rotatable merchandise carriers. Our improved drive system is simpler in construction than are drive systems of the prior art employed in machines having rotary merchandise storage compartments. It is more rugged than such drive mechanisms of the prior art and has a longer life. It is more certain in operation than are systems of the prior art adapted selectively to rotate generally circular merchandise carriers. Mid-cycle jams can be cleared without dismantling the machine.